According to TorrentFreak, the New Zealand judge in the Megaupload case, David Harvey, ruled that the U.S. must hand over any and all evidence it has against Dotcom and Megaupload. When the judge says evidence, he really means all the evidence. Not only must the U.S. hand over the evidence that they have in New Zealand, but also all evidence that the FBI has obtained.
As always, the U.S. objected to the ruling by saying Dotcom doesn't have the right to view the evidence against him during the extradition process. Disagreeing with that, Judge Harvey ruled that Dotcom has a right to mount a proper defense against the accusations levied against him.
If you've been following this case at all, you'll know just how big this is. Every step of the way, the U.S. government has tried every tactic to make this case as unfair as it possibly can. It has attempted to erase the company's servers, denied Dotcom his own property to use as evidence and tried to keep him in prison.
Judge Harvey also made some interesting comments in regards to the case that are worth pointing out as well. He says that the U.S. is trying to apply civil copyright laws to a criminal copyright case. All of the other charges that have been brought against Dotcom rest on whether or not they can prove that Dotcom has indeed violated copyright. The weird mash-up of civil and criminal copyright law makes the case that much harder to actually rule on.
The U.S. has 21 days to hand over the evidence it has against Dotcom. From that point, he will probably start preparing his defense. Dotcom has been confident that he will prove the charges levied against him are insubstantial.
TorrentFreak was kind enough to upload the entire 81-page court document. It's a fascinating read about copyright law and how the Megaupload case has been handled thus far: